Ternary organic active layer material, organic photoelectric detector and application thereof

Abstract

The invention relates to the technical field of preparation of photoelectric functional materials and devices, in particular to a ternary organic active layer material, an organic photoelectric detector and application of the organic photoelectric detector. The ternary organic active layer material comprises a first donor material, a second donor material and an organic acceptor material; the first donor material is D18, the second donor material is any one of PBDB-T, PM6 and PCE-10, and the chemical structural formula of the organic acceptor material is as follows: the ternary organic active layer material has wide light response range capability; the organic photoelectric detector prepared by using the ternary organic active layer material realizes wide light response in a range of 300-1100nm, has the characteristic of wide spectrum response, and also has the advantages of low dark current, high responsivity and high specific detection rate, and lays a foundation for realizing visible light to near-infrared wide spectrum detection of the high-performance photoelectric detector.

Description

Technical Field

[0001] The present invention relates to the technical field of photoelectric functional materials and device preparation, and in particular to a ternary organic active layer material, an organic photodetector and applications thereof. Background Art

[0002] Photodetectors are devices that convert light signals into electrical signals and are widely used in many fields such as imaging systems, environmental monitoring, information communication, and biosensing. Depending on the material, photodetectors can be divided into inorganic photodetectors and organic photodetectors. Among them, although inorganic photodetectors have high chemical stability and electrical properties, their preparation process is complex, costly, and difficult to achieve flexibility, which limits their application in emerging fields such as flexible electronics. In contrast, organic photodetectors have attracted widespread attention due to their advantages such as light weight, low manufacturing cost, and flexible preparation. However, the light response range of traditional organic photodetectors is usually limited to the near-ultraviolet to visible light band, which greatly limits the detection of near-infrared light by organic photodetectors. In addition, traditional organic photodetectors have a high dark current, which greatly reduces the specific detection rate of organic photodetectors.

[0003] Therefore, developing an organic photodetector with both wide spectral response characteristics and low dark current is a technical problem that needs to be urgently solved in this field. Summary of the Invention

[0004] The present invention provides a ternary organic active layer material. In a thin film state, the ternary organic active layer material absorbs light in the range of 300-1100nm and has a wide absorption range. The organic photodetector prepared using the ternary organic active layer material also achieves a wide light response in the range of 300-1100nm and has a wide spectral response characteristic. It also has the advantages of low dark current, high responsiveness and high specific detection rate.

[0005] The present invention also provides an organic photodetector comprising the aforementioned ternary organic active layer material. The organic photodetector achieves a wide light response within the range of 300-1100 nm, exhibits a wide spectral response, and has the advantages of low dark current, high responsivity, and high specific detectivity.

[0006] The present invention also provides a PPG device comprising the aforementioned organic photodetector. Research by the inventors has shown that, when used in a transmissive PPG test, the organic photodetector can detect light in both the visible (640 nm) and near-infrared (950 nm) bands, and can perform both contact and non-contact detection of a person's heart rate and blood oxygen saturation. Therefore, it is suitable for use in PPG devices.

[0007] The first aspect of the present invention provides a ternary organic active layer material, comprising a first donor material, a second donor material, and an organic acceptor material; the first donor material is D18, the second donor material is any one of PBDB-T, PM6, and PCE-10, and the chemical structure of the organic acceptor material is shown in Formula I:

[0008]

[0009] In Formula I, X is independently selected at each occurrence from F, Cl or Br; A is independently selected at each occurrence from R is independently selected at each occurrence from -C 11 H 23 or

[0010] In the ternary organic active layer material as described above, the mass ratio of the first donor material, the second donor material and the organic acceptor material is (0.1-1):1:1.

[0011] In the ternary organic active layer material as described above, the mass ratio of the first donor material, the second donor material and the organic acceptor material is (0.2-0.4):1:1.

[0012] The ternary organic active layer material as described above is obtained by a preparation method comprising the following steps: mixing a first donor material, a second donor material, an organic acceptor material, a liquid additive and an organic solvent to obtain the ternary organic active layer material.

[0013] The ternary organic active layer material as described above, wherein the concentration of the second donor material is 4-12 mg / mL, and the mass percentage of the liquid additive is 0%-1%;

[0014] and / or, the liquid additive comprises 1,8-diiodooctane;

[0015] And / or, the organic solvent includes any one of chlorobenzene, o-dichlorobenzene, chloroform, toluene, xylene, and trimethylbenzene.

[0016] The second aspect of the present invention provides an organic photodetector, comprising a substrate, a transparent conductive electrode, a hole transport layer, a ternary organic active layer, an electron transport layer, and a metal electrode stacked in sequence, wherein the ternary organic active layer is formed by the ternary organic active layer material.

[0017] In the organic photodetector as described above, the thickness of the ternary organic active layer is 100-256 nm.

[0018] The organic photodetector as described above is obtained by a preparation method comprising the following steps:

[0019] Disposing a transparent conductive electrode on the surface of a substrate to obtain a base;

[0020] coating a hole transport layer solution on a surface of the transparent conductive electrode away from the substrate, and drying the solution to form a hole transport layer;

[0021] Coating the ternary organic active layer material on the surface of the hole transport layer away from the transparent conductive electrode, and performing annealing treatment to form a ternary organic active layer;

[0022] coating an electron transport layer solution on a surface of the ternary organic active layer away from the hole transport layer to form an electron transport layer;

[0023] The organic photodetector is obtained by vacuum evaporating a metal electrode on the surface of the electron transport layer away from the ternary organic active layer.

[0024] The organic photodetector as described above, wherein the substrate comprises a PET substrate or a glass substrate;

[0025] And / or, the transparent conductive electrode comprises an ITO electrode;

[0026] And / or, the hole transport layer solution includes a solution prepared by mixing PEDOT:PSS with a first solvent;

[0027] And / or, the electron transport layer solution comprises a solution prepared by dissolving PDINO in a second solvent;

[0028] And / or, the metal electrode material includes silver.

[0029] A third aspect of the present invention provides a PPG device comprising the organic photodetector.

[0030] The solution of the present invention has at least the following effects:

[0031] The ternary organic active layer material provided by the present invention absorbs light in the range of 300-1100nm in a thin film state and has a wide absorption range. The organic photodetector prepared using the ternary organic active layer material achieves a wide light response in the range of 300-1100nm and has a wide spectral response characteristic. It also has the advantages of low dark current, high responsiveness and high specific detection rate.

[0032] The organic photodetector provided by the present invention achieves a wide light response in the range of 300-1100nm by applying the above-mentioned ternary organic active layer material to the organic photodetector, has a wide spectral response characteristic, and also has the advantages of low dark current, high responsiveness and high specific detection rate, laying the foundation for realizing high-performance photodetectors with wide spectral detection from visible light to near-infrared; and the organic photodetector has dual response peaks at 640nm and 950nm, which are closely related to the absorption spectra of oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb), and has potential application value in the field of health monitoring.

[0033] The present invention also provides a PPG device. By applying the above-mentioned organic photodetector to the PPG device, the PPG device can detect light in both visible (640nm) and near-infrared (950nm) bands, and can realize contact and non-contact detection of the human body's heart rate and blood oxygen saturation, providing a new solution for the fields of health monitoring and wearable devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 This is a synthetic route for the organic receptor material ZCJ-1 in Example 1 of the present invention;

[0036] Figure 2 is the H NMR spectrum of the organic acceptor material ZCJ-1 in Example 1 of the present invention;

[0037] Figure 3 This is the mass spectrum of the organic acceptor material ZCJ-1 in Example 1 of the present invention;

[0038] Figure 4 is the chemical structural formula of D18;

[0039] Figure 5 is the chemical structural formula of PBDB-T;

[0040] Figure 6 Schematic diagram of the structure of the organic photodetector in Example 6 of the present invention: 1-glass substrate, 2-ITO electrode, 3-hole transport layer, 4-ternary organic active layer, 5-electron transport layer, 6-metal electrode;

[0041] Figure 7Schematic diagram of the structure of the organic photodetector in Example 10 of the present invention: 7-PET substrate, 8-ITO electrode, 9-hole transport layer, 10-ternary organic active layer, 11-electron transport layer, 12-metal electrode;

[0042] Figure 8 are the absorption spectra of the binary organic active layer material in Example 5 and the ternary organic active layer material in Example 3 in the thin film and solution states, respectively, wherein Figure 8 (a) is the absorption spectrum of PBDB-T:ZCJ-1 solution and D18:PBDB-T:ZCJ-1 solution, Figure 8 (b) shows the absorption spectra of PBDB-T:ZCJ-1 film and D18:PBDB-T:ZCJ-1 film;

[0043] Figure 9 The dark current and responsivity test results of the organic photodetectors (OPDs) in Examples 6-8 and the organic photodetector (OPD) in Example 9 are shown in FIG. Figure 9 (a) is the responsivity test result of the organic photodetector (OPD) in Examples 6-8 and the organic photodetector (OPD) in Example 9, Figure 9 (b) is the dark current test result of the organic photodetector (OPD) in Examples 6-8 and the organic photodetector (OPD) in Example 9;

[0044] Figure 10 1 is the test result of the specific detectivity of the organic photodetector (OPD) in Example 7 and the organic photodetector (OPD) in Example 9;

[0045] Figure 11 The organic photodetector (OPD) in Example 10 is bent;

[0046] Figure 12 The dark current, responsivity and specific detectivity of the organic photodetector (OPD) in Example 10 before and after bending 2000 times are tested. Figure 12 (a) is the responsivity of the organic photodetector (OPD) in Example 10 before bending and after bending 2000 times, Figure 12 (b) is the dark current of the organic photodetector (OPD) in Example 10 before bending and after bending 2000 times, Figure 12 (c) is the specific detectivity of the organic photodetector (OPD) in Example 10 before bending and after bending 2000 times.

[0047] Figure 13 Testing of organic photodetector heart rate monitoring;

[0048] Figure 14Testing of organic photodetectors for blood oxygen saturation monitoring. DETAILED DESCRIPTION

[0049] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0050] Unless otherwise specified, the raw materials and reagents used in the following examples can be obtained from commercial sources; the processes used, unless otherwise specified, are conventional processes in the art.

[0051] It should be noted that the descriptions involving “first”, “second”, etc. in the present invention are only for descriptive purposes and therefore cannot be understood as limiting the present invention.

[0052] In the following description of this embodiment, the terms "include", "comprising", "having" and "containing" are open-ended terms, meaning including but not limited to.

[0053] In the following description of this embodiment, the term "and / or" is used to describe the association relationship between associated objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, B exists alone, and both A and B exist. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0054] The first aspect of the present invention provides a ternary organic active layer material, which includes a first donor material, a second donor material, and an organic acceptor material; the first donor material is D18, the second donor material is any one of PBDB-T, PM6, and PCE-10, and the chemical structure of the organic acceptor material is shown in Formula I:

[0055]

[0056] In Formula I, X is independently selected at each occurrence from F, Cl or Br; A is independently selected at each occurrence from R is independently selected at each occurrence from -C 11 H 23 or

[0057] In the present invention, the ternary organic active layer material absorbs light from 300 to 1100 nm in both thin film and solution forms, exhibiting a wide absorption range. Research has shown that organic photodetectors fabricated using this ternary organic active layer material achieve a broad light response within the 300-1100 nm range, demonstrating a broad spectral response. Furthermore, these organic photodetectors exhibit low dark current, high responsivity, and high specific detectivity.

[0058] In a specific embodiment, in the above-mentioned ternary organic active layer material, the mass ratio of the first donor material, the second donor material and the organic acceptor material is (0.1-1):1:1.

[0059] When the parameters of the mass ratio of the first donor material, the second donor material and the organic acceptor material in the ternary organic active layer material are within the above range, the organic photodetector prepared using the ternary organic active layer material has the advantages of low dark current and high responsiveness in the near-infrared region.

[0060] Illustratively, in the ternary organic active layer material, the mass ratio of the first donor material, the second donor material and the organic acceptor material can be 0.1:1:1, 0.2:1:1, 0.3:1:1, 0.4:1:1, 0.5:1:1, 0.6:1:1, 0.7:1:1, 0.8:1:1, 0.9:1:1 or 1:1:1, etc.

[0061] Furthermore, in the above-mentioned ternary organic active layer material, the mass ratio of the first donor material, the second donor material and the organic acceptor material is (0.2-0.4):1:1, and may be preferably 0.3:1:1.

[0062] When the mass ratio parameters of the first donor material, the second donor material and the organic acceptor material in the ternary organic active layer material are within the above range, the organic photodetector prepared using the ternary organic active layer material has the advantages of lower dark current and higher responsiveness in the near-infrared region.

[0063] For example, in the ternary organic active layer material, the mass ratio of the first donor material, the second donor material and the organic acceptor material may be 0.2:1:1, 0.3:1:1 or 0.4:1:1, etc.

[0064] In a specific embodiment, the ternary organic active layer material is obtained by a preparation method comprising the following steps: mixing a first donor material, a second donor material, an organic acceptor material, a liquid additive and an organic solvent to obtain the ternary organic active layer material.

[0065] The present invention does not impose any particular limitation on the order of adding the raw materials for preparing the ternary organic active layer material, and the process can be carried out according to conventional methods.

[0066] The present invention can prepare a ternary organic active layer material with a wide absorption range through the preparation method.

[0067] In a specific embodiment, in the above-mentioned ternary organic active layer material, the concentration of the second donor material is 4-12 mg / mL, and the mass percentage of the liquid additive is 0%-1%.

[0068] In the above-mentioned ternary organic active layer material, the concentration of the second donor material can be in the range of any one of 4 mg / mL, 5 mg / mL, 6 mg / mL, 7 mg / mL, 8 mg / mL, 9 mg / mL, 10 mg / mL, 11 mg / mL, and 12 mg / mL, or any two thereof;

[0069] The mass percentage content of the liquid additive may be any one of 0%, 0.2%, 0.4%, 0.6%, 0.8%, 1%, or any two of the following.

[0070] It can be understood that when the mass percentage of the liquid additive is 0%, the ternary organic active layer material is obtained by mixing the first donor material, the second donor material, the organic acceptor material and the organic solvent.

[0071] When the concentration of the second donor material or the mass percentage of the liquid additive is within the above range, the ternary organic active layer material is used to prepare an organic photodetector (OPD), which can enable the prepared OPD to have the advantages of low dark current, high responsiveness and high specific detection rate in the near-infrared region.

[0072] In a specific embodiment, the liquid additive includes 1,8-diiodooctane.

[0073] When 1,8-diiodooctane is used as a liquid additive, the ternary organic active layer material is used to prepare an organic photodetector (OPD), which can make the OPD have a higher responsivity.

[0074] In a specific embodiment, the organic solvent includes any one of chlorobenzene, o-dichlorobenzene, chloroform, toluene, xylene, and trimethylbenzene.

[0075] The second aspect of the present invention provides an organic photodetector, comprising a substrate, a transparent conductive electrode, a hole transport layer, a ternary organic active layer, an electron transport layer, and a metal electrode stacked in sequence, wherein the ternary organic active layer is formed of the above-mentioned ternary organic active layer material.

[0076] In the present invention, the organic photodetector has a multilayered structure. It achieves a broad light response within the 300-1100 nm range, exhibiting a wide spectral response, low dark current, high responsivity, and high specific detectivity. Furthermore, the organic photodetector exhibits dual response peaks at 640 nm and 950 nm, which are closely related to the absorption spectra of oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb), making it suitable for use in photoplethysmographic (PPG) devices.

[0077] In a specific embodiment, the thickness of the ternary organic active layer is 100-256 nm.

[0078] When the thickness of the ternary organic active layer is within the above range, the organic photodetector prepared using the ternary organic active layer not only achieves a wide light response in the range of 300-1100nm and has a wide spectral response characteristic, but also has the advantages of lower dark current, higher responsiveness and higher specific detection rate.

[0079] In a specific embodiment, the organic photodetector is obtained by a preparation method comprising the following steps:

[0080] Disposing a transparent conductive electrode on the surface of a substrate to obtain a base;

[0081] Coating a hole transport layer solution on a surface of the transparent conductive electrode away from the substrate, and forming a hole transport layer after drying;

[0082] A ternary organic active layer material is coated on the surface of the hole transport layer away from the transparent conductive electrode, and is annealed to form a ternary organic active layer;

[0083] Coating an electron transport layer solution on the surface of the ternary organic active layer away from the hole transport layer to form an electron transport layer;

[0084] The organic photodetector is obtained by vacuum evaporating a metal electrode on the surface of the electron transport layer away from the ternary organic active layer.

[0085] The present invention does not particularly limit the specific coating method, and the coating can be carried out in a conventional manner in the art, for example, by spin coating, blade coating, drop coating, etc.

[0086] In the present invention, the above-mentioned substrate can be purchased through commercial channels, or can be prepared according to methods known in the art: for example, a transparent conductive electrode can be sputtered on the surface of a substrate using magnetron sputtering preparation technology to obtain the substrate.

[0087] The present invention can prepare an organic photodetector with wide spectral response characteristics, low dark current, high responsiveness and high specific detectivity through the preparation method.

[0088] In a specific embodiment, the substrate includes a PET substrate or a glass substrate.

[0089] In a specific embodiment, the transparent conductive electrode includes an ITO electrode.

[0090] In a specific embodiment, the hole transport layer solution includes a solution prepared by mixing PEDOT:PSS with a first solvent.

[0091] Furthermore, the first solvent includes water. The present invention does not impose any particular limitation on the specific type of water, which may be any conventional type known in the art, for example, distilled water.

[0092] In a specific embodiment, the electron transport layer solution includes a solution prepared by dissolving PDINO in a second solvent.

[0093] Furthermore, the second solvent includes methanol.

[0094] In a specific embodiment, the metal electrode material includes silver.

[0095] A third aspect of the present invention provides a PPG device comprising the above-mentioned organic photodetector.

[0096] Research by the inventors has shown that the organic photodetector has dual response peaks at 640nm and 950nm, which are closely related to the absorption spectra of oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb). Therefore, it is applied to photoplethysmographic (PPG) devices. The PPG device can detect light in both visible (640nm) and near-infrared (950nm) bands, and can realize contact and non-contact detection of human heart rate and blood oxygen saturation, which has potential application value.

[0097] The present invention is further described below through specific examples.

[0098] The CH2FBr used in the following examples was synthesized by referring to the method in the reference (A case study of comparing twodimerized acceptor molecules built by different branch-connected andterminal-connected approaches, SCIENCE CHINA Chemistry, 67, 1687-1696(2024)).

[0099] Example 1

[0100] Figure 1 The synthetic route of the organic receptor material ZCJ-1 of Example 1 of the present invention is as follows: Figure 1 As shown, the preparation method of the organic receptor material ZCJ-1 of this embodiment includes the following steps:

[0101] S1: In a two-necked round-bottom flask, 0.17 g of CH2FBr (compound 1), 0.72 g of hexamethyltin ditin, 0.07 g of tetrakistriphenylphosphine palladium, and 20 mL of dry chromatographically pure toluene were added. Under argon protection, the mixture was heated to reflux at 120°C for 12 hours, then cooled to room temperature. The solvent toluene was removed by vacuum distillation, and the mixture was purified by column chromatography on alkaline alumina to obtain compound 2.

[0102] S2: In another two-necked round-bottom flask, 0.18 g of compound 2, 0.13 g of 4,6-dibromo-3-fluorothieno[3,4-b]thiophene-2-carboxylic acid octyl ester, 0.014 g of tris(dibenzylideneacetone)dipalladium (Pd2(dba)3), 0.019 g of tris(o-methylphenyl)phosphine (P(o-tol)3) and 20 mL of dry chromatographically pure toluene were added. Under argon protection, the mixture was heated at reflux at 120°C for 12 hours and then cooled to room temperature. The solvent toluene was removed by distillation under reduced pressure, and compound 3 was obtained by column chromatography.

[0103] S3: 0.21 g of compound 3, 0.14 g of 2-(5,6-difluoro-2,3-dihydro-3-oxo-1H-inden-1-ylidene)propionitrile, 0.3 mL of ultra-dry pyridine and 30 mL of chloroform were added to a round-bottom flask. Under argon protection, the mixture was heated under reflux at 65° C. for 12 hours and then cooled to room temperature. The reactants were added to 70 mL of methanol for precipitation, filtered, and washed three times with methanol. Afterwards, a black solid, the organic receptor material ZCJ-1 (0.1 g, 40% yield) with the chemical structure shown in Formula II was obtained by column chromatography. The H NMR spectrum of the organic receptor material ZCJ-1 is shown in FIG. Figure 2 As shown in the mass spectrum Figure 3 As shown:

[0104]

[0105] Example 2

[0106] This embodiment provides a method for preparing a ternary organic active layer material, comprising:

[0107] D18 (chemical structure as Figure 4 As shown), PBDB-T (chemical structure as shown Figure 5) and ZCJ-1 (the organic acceptor material ZCJ-1 prepared in Example 1) were mixed with 1,8-diiodooctane (DIO) and chlorobenzene in a mass ratio of 0.2:1:1, and the mixture was uniformly mixed to obtain a ternary organic active layer material; in the ternary organic active layer material, the concentration of PBDB-T was 6 mg / mL, and the mass percentage of 1,8-diiodooctane (DIO) was 0.4%.

[0108] Example 3

[0109] The preparation method of the ternary organic active layer material provided in this embodiment is basically the same as that in Example 2, except that the mass ratio of D18, PBDB-T and ZCJ-1 is 0.3:1:1.

[0110] Example 4

[0111] The preparation method of the ternary organic active layer material provided in this embodiment is basically the same as that in Example 2, except that the mass ratio of D18, PBDB-T and ZCJ-1 is 0.4:1:1.

[0112] Example 5

[0113] This embodiment provides a method for preparing a binary organic active layer material, comprising:

[0114] PBDB-T and ZCJ-1 (the organic acceptor material ZCJ-1 prepared in Example 1) were mixed with 1,8-diiodooctane (DIO) and chlorobenzene in a mass ratio of 1:1, and the mixture was uniformly mixed to obtain a binary organic active layer material; in the binary organic active layer material, the concentration of PBDB-T was 6 mg / mL, and the mass percentage of 1,8-diiodooctane (DIO) was 0.4%.

[0115] Example 6

[0116] This embodiment provides a method for preparing an organic photodetector. The schematic diagram of the structure of the organic photodetector is shown in FIG. Figure 6 shown.

[0117] The method for preparing the organic photodetector provided in this embodiment includes the following steps:

[0118] (1) In an ultrasonic bath, a glass-ITO substrate (17×17 mm, purchased from Jiaxing Hepu Optoelectronics Technology Co., Ltd.) was ultrasonically cleaned with detergent water, deionized water, acetone, and isopropyl alcohol for 15 minutes each. The surface of the glass-ITO substrate was then blown dry with a nitrogen gun. Subsequently, the glass-ITO substrate was treated with ultraviolet light in a UV ozone chamber for 15 minutes to obtain a clean glass-ITO substrate (the glass-ITO substrate was obtained by providing an ITO electrode 2 on the surface of a glass substrate 1).

[0119] (2) PEDOT:PSS (Clevios P ​​AI4083) and distilled water were mixed and diluted in a volume ratio of 1:1, and after being fully dispersed by ultrasound, the mixture was filtered using a PES 0.45 μm pore size filter membrane to obtain a hole transport layer solution; the hole transport layer solution was spin-coated on the surface of the ITO electrode 2 away from the clean PET substrate 1, and the mixture was dried at 150°C for 15 minutes and placed in a nitrogen-filled glove box to form a hole transport layer 3;

[0120] (3) Spin-coating a ternary organic active layer material (the ternary organic active layer material prepared in Example 2) on the surface of the hole transport layer 3 away from the ITO electrode 2, and annealing to form a ternary organic active layer 4 with a thickness of 120 nm;

[0121] (4) dissolving PDINO (CAS No.: 1558023-86-1) in methanol to obtain an electron transport layer solution (the concentration of PDINO in the electron transport layer solution is 2 mg / mL); spin-coating the electron transport layer solution on the surface of the ternary organic active layer 4 away from the hole transport layer 3 to form an electron transport layer 5;

[0122] (5) Control the vacuum degree during vacuum evaporation to 2×10 -5 torr, a layer of silver (Ag) with a thickness of 100 nm is vacuum evaporated on the surface of the electron transport layer 5 away from the ternary organic active layer 4 as a metal electrode 6 to obtain an organic photodetector.

[0123] Example 7

[0124] The preparation method of the organic photodetector provided in this embodiment is basically the same as that in Example 6, except that the ternary organic active layer material used is the ternary organic active layer material prepared in Example 3.

[0125] Example 8

[0126] The preparation method of the organic photodetector provided in this embodiment is basically the same as that in embodiment 6, except that the ternary organic active layer material used is the ternary organic active layer material prepared in embodiment 4.

[0127] Example 9

[0128] The preparation method of the organic photodetector provided in this embodiment is basically the same as that of Example 6, except that the ternary organic active layer material is replaced by a binary organic active layer material (the binary organic active layer material prepared in Example 5).

[0129] Example 10

[0130] This embodiment provides a method for preparing an organic photodetector. The schematic diagram of the structure of the organic photodetector is shown in FIG. Figure 7 As shown, the preparation method of the organic photodetector provided in this embodiment is basically the same as that in Example 6, except that:

[0131] The Glass-ITO substrate was replaced with a PET-ITO substrate (17×17 mm, purchased from Jiaxing Hepu Optoelectronics Technology Co., Ltd.).

[0132] Performance Testing

[0133] (1) Absorption spectrum test of ternary organic active layer materials

[0134] The binary organic active layer material in Example 5 and the ternary organic active layer material in Example 3 were dissolved in chloroform to obtain a PBDB-T:ZCJ-1 solution (PBDB-T:ZCJ-1) and a D18:PBDB-T:ZCJ-1 solution (D18:PBDB-T:ZCJ-1); the PBDB-T:ZCJ-1 solution (PBDB-T:ZCJ-1) and the D18:PBDB-T:ZCJ-1 solution (D18:PBDB-T:ZCJ-1) were dissolved in chloroform. J-1) were respectively spun on the surface of a quartz plate to obtain a PBDB-T:ZCJ-1 thin film (PBDB-T:ZCJ-1) and a D18:PBDB-T:ZCJ-1 thin film (D18:PBDB-T:ZCJ-1); the absorption spectra of the PBDB-T:ZCJ-1 solution, the D18:PBDB-T:ZCJ-1 solution, the PBDB-T:ZCJ-1 thin film and the D18:PBDB-T:ZCJ-1 thin film were tested, and the results are shown in FIG. Figure 8 shown.

[0135] Depend on Figure 8 As can be seen from (a) and (b), the binary organic active layer material and the ternary organic active layer material both show two obvious absorption peaks in the thin film and solution states; the cutoff absorption from solution to thin film has undergone a large red shift, indicating that the binary organic active layer material and the ternary organic active layer material have good stacking; in the thin film absorption, the two maximum absorption peaks of the binary organic active layer material and the ternary organic active layer material are both near 640nm and 950nm, which is closely related to the absorption spectrum of oxygenated hemoglobin (HbO2) and deoxygenated hemoglobin (Hb).

[0136] (2) Performance test of organic photodetectors

[0137] ① The dark current and responsivity of the organic photodetectors (OPDs) in Examples 6-8 and the organic photodetector (OPD) in Example 9 were tested respectively. The test results are as follows: Figure 9 and as shown in Table 1;

[0138] Dark current (J d): The tests were conducted in an electromagnetic shielding box to reduce external electromagnetic interference. All tests were performed in air. The current density, i.e., dark current, was recorded using a semiconductor device analyzer (KEYSIGHT, B1500A).

[0139] Responsivity (R): First, measure the external quantum efficiency (EQE). EQE measurements are performed in the 300-1100nm range using an Enlitech QE-R EQE system equipped with a standard silicon diode. Then, calculate the responsivity (R) according to the following formula:

[0140] Where EQE is the external quantum efficiency, λ input is the wavelength of incident light, 1240 is a fixed parameter.

[0141] Table 1 Test results

[0142]

[0143] The dark current of the photodetector demonstrates its ability to detect small signals. Figure 9 (b) Combined with Table 1, it can be seen that the dark current of the organic photodetectors in Examples 6-8 is lower than that of the organic photodetector in Example 9, which illustrates that the organic photodetectors in Examples 6-8 of the present invention have the advantage of low dark current and can distinguish light signals with smaller intensity.

[0144] The degree of responsivity can reflect the sensitivity of the photodetector. Figure 9 (a) Combined with Table 1, it can be seen that the organic photodetector in Example 7 shows the highest responsivity, indicating that the organic photodetector prepared with D18:PBDB-T:ZCJ-1 (0.3:1:1) has higher sensitivity than the organic photodetector prepared with PBDB-T:ZCJ-1 (1:1); the responsivity of the organic photodetector in Example 7 in the near-infrared region (950nm) can reach 0.41AW -1 , which has the advantage of high responsiveness in the near-infrared region.

[0145] Responsivity is also an indicator to measure the response quality of photodetectors. The higher the responsivity, the better the sensitivity of the detector. Figure 9 As shown in (a), PBDB-T:ZCJ-1 exhibits good light absorption in the range of 300-1100nm. The introduction of another donor material D18 does not change the absorption waveform, and D18:PBDB-T:ZCJ-1 also exhibits good light absorption in the range of 300-1100nm. When the mass ratio of D18:PBDB-T:ZCJ-1 is 0.3:1:1, the responsivity of the organic photodetector reaches its maximum value. Figure 9(a) Combined with Table 1, the responsivity of the organic photodetector in Example 7 at 640nm is 0.34AW -1 , the responsivity at 950nm is 0.41AW -1 , the responsivity at 1000nm is 0.33AW -1 , demonstrating that the organic photodetector has photoresponsive properties in the visible and even near-infrared spectra, laying the foundation for high-performance photodetectors with wide-spectrum detection from the visible to the near-infrared. Furthermore, the organic photodetector has dual response peaks at 640nm and 950nm, which are closely related to the absorption spectra of oxyhemoglobin (HbO2) and deoxyhemoglobin (Hb), making it suitable for use in photoplethysmographic (PPG) devices.

[0146] The above results show that the organic photodetectors in Examples 6-8 of the present invention achieve a broad light response in the range of 300-1100 nm, exhibiting a wide spectral response, low dark current, and high responsivity. Among them, the organic photodetector in Example 7 has the highest responsivity.

[0147] ② The organic photodetectors in Example 7 and Example 9 were tested for specific detection rate. The test results of specific detection rate are as follows: Figure 10 and as shown in Table 2;

[0148] Specific Detection Rate (D*): Specific Detection Rate (D*) is calculated according to the following formula:

[0149] Among them S n is the device noise, R is the responsivity, and A is the device area (0.042 cm -2 ).

[0150] Table 2 Test results

[0151] project D*,0V(Jones)@950nm D*,0V(Jones)@1000nm Example 7 <![CDATA[4.1×10 12 ]]> <![CDATA[3.2×10 12 ]]> Example 9 <![CDATA[1.5×10 11 ]]> <![CDATA[3.2×10 11 ]]>

[0152] Detectivity (D*) is an important parameter to measure the performance of photodetectors. The higher the detectivity, the stronger the detection capability of the detector. Figure 10 Combined with Table 2, it can be seen that in the spectral range of 300-1100 nm, the specific detectivity of the organic photodetector in Example 7 (D18:PBDB-T:ZCJ-1=0.3:1:1) is greater than the specific detectivity of the organic photodetector in Example 9 (PBDB-T:ZCJ-1=1:1); the specific detectivity of the organic photodetector in Example 7 in the near-infrared region (950 nm) can reach 4.1×10 12 Jones, has the advantage of high specific detectivity in the near-infrared region.

[0153] ③ The organic photodetector in Example 10 was subjected to a bending stability test as follows:

[0154] The organic photodetector in Example 10 was bent 2000 times with a bending radius of 5 mm each time to obtain an organic photodetector after being bent 2000 times; Figure 11 The organic photodetector in Example 10 is bent; the dark current (J d ), responsivity (R) and specific detection rate (D*) tests, the test method is the same as above, the test results are as follows Figure 12 and shown in Table 3.

[0155] Table 3 Test results

[0156]

[0157] from Figure 12 From (a)-(c) in combination with Table 3, it can be seen that the organic photodetector is flexible, and its performance (dark current, responsiveness or specific detection rate) before and after bending remains basically unchanged or decreases by a very small percentage, indicating that it has excellent bending stability (mechanical stability).

[0158] (3) Testing of heart rate monitoring and blood oxygen saturation monitoring using organic photodetectors

[0159] ①Testing of organic photodetector heart rate monitoring

[0160] The organic photodetector in Example 7 was used to perform heart rate monitoring tests at 640 nm and 950 nm, and at distances of 0 cm, 1 cm, 2 cm, 3 cm, 5 cm, and 7 cm. Figure 13 The heart rate results during normal breathing obtained when the organic photodetector was used for the transmissive PPG test are given and summarized in Table 4.

[0161] Table 4 Heart rate results

[0162]

[0163] Depend on Figure 13 Combined with Table 4, it can be seen that the heart rate tests at different distances are within the error range, indicating the accuracy and consistency of the measurements.

[0164] ②Testing of blood oxygen saturation monitoring using organic photodetectors

[0165] The organic photodetector in Example 7 was used to perform blood oxygen saturation monitoring tests at distances of 0 cm, 1 cm, 2 cm, 3 cm, 5 cm, and 7 cm, respectively. Figure 14The blood oxygen saturation results during normal breathing obtained when the organic photodetector was used for the transmissive PPG test are given and summarized in Table 5.

[0166] Table 5 Blood oxygen saturation results

[0167]

[0168] Depend on Figure 14 Combined with Table 5, it can be seen that the tests on blood oxygen saturation at different distances are within the error range, indicating the accuracy and consistency of the measurement.

[0169] The above results show that when the organic photodetector in Example 7 is used for transmissive PPG testing, it can detect light in both the visible (640nm) and near-infrared (950nm) bands, and can realize contact and non-contact detection of the human body's heart rate and blood oxygen saturation.

[0170] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A ternary organic active layer material, characterized in that: The ternary organic active layer material includes a first donor material, a second donor material and an organic acceptor material; the first donor material is D18, the second donor material is any one of PBDB-T, PM6, and PCE-10, and the chemical structure of the organic acceptor material is shown in Formula I: In Formula I, X is independently selected at each occurrence from F, Cl or Br; A is independently selected at each occurrence from R is independently selected at each occurrence from -C 11 H 23 or 2. The ternary organic active layer material according to claim 1, characterized in that: In the ternary organic active layer material, the mass ratio of the first donor material, the second donor material and the organic acceptor material is (0.1-1):1:

1.

3. The ternary organic active layer material according to claim 2, characterized in that: In the ternary organic active layer material, the mass ratio of the first donor material, the second donor material and the organic acceptor material is (0.2-0.4):1:

1.

4. The ternary organic active layer material according to claim 3, characterized in that: The ternary organic active layer material is obtained by a preparation method comprising the following steps: mixing a first donor material, a second donor material, an organic acceptor material, a liquid additive and an organic solvent to obtain the ternary organic active layer material.

5. The ternary organic active layer material according to claim 4, characterized in that: In the ternary organic active layer material, the concentration of the second donor material is 4-12 mg / mL, and the mass percentage of the liquid additive is 0%-1%; and / or, the liquid additive comprises 1,8-diiodooctane; And / or, the organic solvent includes any one of chlorobenzene, o-dichlorobenzene, chloroform, toluene, xylene, and trimethylbenzene.

6. An organic photodetector comprising a substrate, a transparent conductive electrode, a hole transport layer, a ternary organic active layer, an electron transport layer, and a metal electrode stacked in sequence, characterized in that: The ternary organic active layer is formed of the ternary organic active layer material according to any one of claims 1 to 5.

7. The organic photodetector according to claim 6, wherein: The thickness of the ternary organic active layer is 100-256 nm.

8. The organic photodetector according to claim 6, wherein: The organic photodetector is obtained by a preparation method comprising the following steps: Disposing a transparent conductive electrode on the surface of a substrate to obtain a base; coating a hole transport layer solution on a surface of the transparent conductive electrode away from the substrate, and drying the solution to form a hole transport layer; Coating the ternary organic active layer material according to any one of claims 1 to 5 on the surface of the hole transport layer away from the transparent conductive electrode, and performing annealing treatment to form a ternary organic active layer; coating an electron transport layer solution on a surface of the ternary organic active layer away from the hole transport layer to form an electron transport layer; The organic photodetector is obtained by vacuum evaporating a metal electrode on the surface of the electron transport layer away from the ternary organic active layer.

9. The organic photodetector according to claim 8, wherein The substrate includes a PET substrate or a glass substrate; And / or, the transparent conductive electrode comprises an ITO electrode; And / or, the hole transport layer solution includes a solution prepared by mixing PEDOT:PSS with a first solvent; And / or, the electron transport layer solution comprises a solution prepared by dissolving PDINO in a second solvent; And / or, the metal electrode material includes silver.

10. A PPG device, characterized in that: The organic photodetector comprises the organic photodetector according to any one of claims 6 to 9.

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